Method for recycling metals from swarf

Abstract

A method for recycling metals from swarf includes steps of removing oil in swarf by means of surfactant having a feature of strong hydrophilicity. The steps involves repeated stirring and washing, separating solid from liquid, and separating oil from water so as to force oil separate from the surface of solid, finishing all the steps in 10–30 minutes. Metals after finished the treatment may have only 1% of oil remained thereon, possible to be reused in metalworking. Oil and washing solution are also reusable after treated, so the method is effective both for treating waste and for recycling resources.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]This invention relates to a method for recycling metals from swarf, particularly to one capable to separate oil in swarf by means of aqueous surfactant solution within thirty minutes with oil removing efficiency as high as more than 99%.[0003]2. Description of the Prior Art[0004]Grinding and cutting operation is a cutting process that removes material from the workpiece by the action of abrasive grains. It is the most important process in the metal working industry that manufacture high speed cutting tools, bearings, and special metal devices. In order to increase smoothness and lower temperature in grinding and cutting and enhance the surface quality of the workpiece cutting fluids is commonly used, resulting in swarf of metal mixed with cutting fluids.[0005]As the metalworking industry has been growing year and year, swarf produced has been increased substantially, and some sward may contain chlorinated compounds and ...

AI Technical Summary

Benefits of technology

This method effectively reduces swarf oil content to less than 1%, enabling safe recycling and reuse of metals, lowering treatment costs, and promoting resource recovery while being economically viable and suitable for industrial use.

Problems solved by technology

As the metalworking industry has been growing year and year, swarf produced has been increased substantially, and some sward may contain chlorinated compounds and heavy metals belonging to harmful toxic waste, and its treatment has been looming up as a serious problem.

For example, metalworking industry in South Carolina State in USA, swarf produced every year surpasses 3 million tons, and that produced in the whole world may be extremely enormous, directly threatening business of the metalworking industry.

In Taiwan ten thousand tons of swarf is produced every year, and liable to increase year by year, with the expense for treating also increasing day-by-day, seriously affecting existence of the metalworking industry.

If it is dissolved, metals can be recovered for recycle, but oil is impossible to be recovered and residue has to be disposed of.

But any useful resource is impossible to be recovered in case of burying.

As there are disadvantages that a large quantity of washing solution is required, the time needed for washing is long, and the solution after washing cannot be reused, those surfactants have to be improved.

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